Base stations and mobile devices may exchange data in unlicensed spectrum. As demand for mobile services and high data rates increases, various challenges related to reliability and capacity may arise. In an example scenario, a large number of users may communicate in the unlicensed spectrum, which may affect performance in terms of interference, range, capacity, throughput and/or other aspects. In another example scenario, a target latency for a user and/or application may be relatively low, and it may be challenging for the system to deliver in an efficient manner. Accordingly, there is a general need for methods and systems to implement communication between the base station and the mobile devices in these and other scenarios.